Whirlwind prop notice??

[bda]

I saw someone mentioned that there is a notice out on the Whirlwind ground adjustable props.
I did not get one.
Has anyone seen this notice? If so can I get a copy?

 

[gdafoe]

I didn't get a notice either but found this:

https://whirlwindpropellers.com/aircraft/wp-content/uploads/2025/04/WW-ASB-61-001.pdf

 

[Steve Pierce]

I have a friend here that built a RANs S21 Outbound with this prop and found a broken bolt.

 

[courierguy]

Same deal here in Idaho, another 21 even. I think he found more than one though, or maybe one, twice.

 

[MtCoyote]

I have a whirlwind prop on a o-360 with a saber spacer. The black bolts that came with the prop galled in sabers lug inserts. After the second occurrence Saber sourced me some harder bolts. Problem seems to be solved.

 

[brownbear]

I have heard of the broken bolts and wondered why it seems to be on the S 21 with the o340
I have run this propeller for 1000 or more hours and 700 of them being on an 0340.
I do not have electronic ignition?

 

[stewartb]

The 340 is stroked. If you ask a propellor engineer they'll likely point to the power pulse of that engine contributing to the problem. In recent years Whirlwind has dropped the engine compression threshold for their prop applications. In discussions with their engineers they've had issues with props on engines that have high compression due to the acceleration of the prop during the power stroke. I'd bet they'd say the same issue applies to the 340. I still use my prop and will continue to. WW advised me to inspect often, and said I wouldn't suffer an instant failure but that the hub will wear out faster than it would on a lower compression engine. For you ground adjustable guys, checking prop bolts shouldn't be much of a burden.

For curiosity's sake, is the position of these broken bolts in the hub consistent? In my imaginary mind movie I'd bet the outboard bolts are the issue since they'd have the highest loads from flexing prop blades.